Rotary well drill



i Patented v".ug. 9, 1927.

"UNITED STATES PATENT o '1,638,337 FFICE.

Itozriamr4 WELL DRILL.

Applicationvledl'llay 25,1925.; `Serial No, 32,691.v

This invention is for the purpose -of the rapid rotary drilling ofwells, chieiiy oil wells of relatively large diameter. i

This is a rotary drill and the invention e consists in the combinationwith a Iish tail or other bit for piloting the drilling apparatus, ofimproved means which follows the fish tail bit for enlarging the bore ofthe hole made by the sh tail bit. This enlarglo ing means, therefore, isin the nature of a reamer.

The reamer is such that after it has been introduced into the well pipeand passes the lower end thereof, it will expand and drill M the holelarger below the pipe, like a reamer.

act on the cutter lholder' to .push it outward into the expandedposition. The cutter holder is mounted in a vertical recess and 1ssubstantially vertically movable with shoulders which limit `thedownwardmovement thereof so that thecons'truction is relatively simple and easyto make and mount and the cutter holders extendlrelatively far in theirseats or recesses, whichmakes them stronge, and they and Asaid'recessesare free from the 30. central water'passage in the drilling appa-Vratus, so that the water would not interfere with the operation of thecutter "holders,

The full nature of the invention will be understood from theaccompanying drawings andthe following description and claims:

In the drawings Fig. 1 is a central vertical section through thewelldrilling apparatus, the upper portion being broken away: j and thelower portion shown in side elevation, and with the central part of thefish 'tail bit broken away and one cutter holder shown in elevation.Fig. 2 isa similar view showing the drilling apparatus lbelow the lowerend of the -well pipe in drilling condition but with the fish tail bitlargely brokf en away and one cutter holder shown .in elevation. Fig. 3is a horizontal section of line 3-3 of Fig. 1. Fig. 4 is a verticalsection on the broken dotted' line 4 4 of .F-ig. l. Fig.'5 is theperspective view of a cutter holder centrally broken away.

Thereis shown herein an oil well pipe 10 and within it there is atubular drilling operation. The lower end of the stem is -of the cutterholder.

stein 11 which is rotated during the drilling internally;tl-ireadedtoreceive the upper end of the reamer orwell drill'in apparatus consistsof a central 2(body portion 12 having a central upwardly eXtendinreduced portion 13 externally tlireade to'l screw into the lower end ofthe stem l1. Immediately below said reduced portion 13 tlie body portion12 is'enlarged and externally threaded to receive a vcap 14 which screwsthereon. Below the said last mentioned threaded'por'tionthe body 12 isenlarged so as to provide annular and downwardly sloping shoulders 15.At said shoulders the diameter of said Ibody 12 is almostv the same asthe internal diameter of the well tube, see Fig. 3.' Below the shoulderportion said bod its lowerendv proviy ed with an internally threadedbore 16 into which the upper end as shown. L y

In diametrically opposite sidesiV of the of the iish tail bit 17 screwsand is secured,

shouldered portion l5 of the body 12 there `are vertical -grooves orrecesses 2O open at 12 is reduce'd and at tool. This l the top and'bottom, and each side wall of said recesses 20 vhas a vertical rib 21 asseen in Fig. 3, the two ribs projecting toward each otherso as toreducethe ywidth of the outer portion or opening of the recessesl 20- above ahorizontal'shoulder 22 in each wall as seen in F ig.' 4. lIn other wordsthe vertical recesses 20 are transversely enlarged above the shoulders22 by the sidewalls being cut out somewhat so as to leave said ribs 21and shoulders 22.

The cutter holders 30 have in their lower ends round rotatable beveledcutters 31. The upper portion of eachcutter holder 30 is widened to formlateralshoulders 32, as seen in Figs. 3 and.4.` The cutter holder isinsertable in said recess from above and the widened portions 32 thereoffit in the 4widened portions of the upper part of'said recess,so thatthe shoulders 32 on the cutter holders and the shoulders 22 in the.walls of t-he recess prevent the downward escape'of the cutter holders,and the ribs 21 in the walls of the recess co-operates with theshoulders 32 to prevent the outward escape The depth of the upperportion of the recess 20 is greater than the thickness of the upperportion of the cutter holder so that the lower end of the cutter holdercan be moved out-ward further from the center of the device, as shown inFig. 2, to expand the cuttersfor enlarging 4ers are expanded, a

lbody or reaming the hole cut 'by the fish taily When `the cutter holderis'in its ,outtingfo'rf inclined position, as seen in Fig. 2, the outerfaces of the shoulders 32 thereofv engage the ribs 21. The side of thecutter holder is shown-in Fig. pand shoulders 32 are beveled downwardand. inward. When the cutter holders are in their contracted osition, asshown in' Fig. 1, the inner sur ace thereof However, the body 12 of thedevice is providedwith small lateral water passages `41 opening into thelower parts of the recesses 2O for cooling the cutters. `The ring 34 isheld in true position with reference to the recesses 2O by 'a pin 42, asshown in Fig. 4. I

'By pivotally mounted ismeant herein is almost vertical, ybut when thecutter holdv s" shown in Fig. 2,. the in! ner. surface is at quite' aninclination orv` thel angle to the body 12 of the-deviceand their theforward faces of the-shoulders `32 are vertical and engage the 'verticalribs 21,v and thereby the cutter holdersareheld firmly-in lace.` A'

The cutter holders 30 are connected with o1-from the position shown in 1to that that the upper end of the cutter holder is mounted so the lowerend may moveoutward Ashown in Fig. 2, or the reverse, the upper ,end,thereofy being held by means substantially in the nature of a pivot soas to allow a ring 34 b y a contractile spring 35. 4 The ring ,34 has aseat 36 the upper end of the therein by a pin 37. The upper end' of eachcutter holder has a vertical recess 39 for receiving the lower end ofthe spring 35 and it is'securedtherewi'th by-a'pin 38. The ring 34 isheld down on the shoulders 15 0f the cut out for receiving s in Fig. 1the springs 35 hold them upward with the beveled surfaces 39 of thecutter holders bearing against the inclined surface 34 and this actionofthe springs 35 tends to force outwardly the lower ends of the cutterholders, so that when the cutter holders pass well tube 10, they will beforced out as shown in Fig. 2, intotheir expanded or cutting position,and so that they will engage the wall-of the well drilled bythe fishtail or in which the tube 10 extends, and when the drill is rotated'willcut the wall of the well and enlarge the well.

spring and iti-is, held 12 by the cap 14, and the lower sur` down belowthe bottom of thev It is thus seen that the cutter holders are stronglyheld in their mounting and are yet capable of assuming their contractedand expanded great strain and when the well drill is elevated in thetube, the cutter holderswill automatically be moved by the lower end ofthe well tube into their substantially vertical contracted positionshown in Fig.v 1.

Also it is to be noted that the mounting of the cutter holders is remotefrom the water passage 40 down through the center of the drill so thatnothing can pass therefrom into the recesses in which the cutter holdersare mounted and no dirt or mud ass from the latter to the water passageand) choke it.

positions. They will withstand such pivotal action of the cutter holder.

The invention claimed is: 'l

1. Rotary well drilling apparatus having a rotary` body portion adaptedto be' introduced through a well pipe. and having the y .upper endthereof reduced and threaded and S below said reduced portion havingupwardly and-inwardly inclined' shoulders and oppositely locatedverticalrecesses, a rind surrounding the contractedtportion and fitting down onsaid shoulders, a cutter holder loosely mounted', in each recess andhaving' the upper end beveled .to engage the inlclined surface ofthering, said ring and cutter holder havin spring seats therein, acontractile spring" ounted in 'said seats yand secured at each end tothering and cutter holder respectively, .and a cutter mounted in the lowerend ofthe cutter holder.

2. Rotary well drilling apparatus duced through a well pipe and havingthe upper'end thereof reduced and threaded and below said reducedportion having upwardly and inwardly inclined shoulders and 0ppositelylocated vertical l recesses, a ringvr y ir surrounding the contractedportion and iittinfr down on said shoulders, a cutter holder l looselymounted in each recess and having the upper end beveled to engage theinclined surface of the ring. said ring and cutter holder'having springseats therein, a con-v tractile spring mounted in said seats land,`secured at each end to the ring and cutter holder respectively; a cuttermounted inV the` lower end of the cutter holder, and a screw cap on theupper reduced end of the body portion for holding-said ring in place.l

3. Rotary well drilling apparatus having a rotary body portion adaptedtobe introduced through a well pipe land having'diam'etrically oppositevertical recesses with the upper portion of each recess venlarged at itssides so as to leave shoulders at the lower 1 part thereof and a pair ofvertical ribs at the outer portion thereof, a cutter holder in eachrecess with the upper end thereof provided with lateral extensions forfitting in the enlarged upper end of the yrecess and providingshoulders'for engaging the shoulders and ribs in the walls of the recessto prevent vthe escape of the cutter holder and having a rotary bodyportion adapted -to be intro-` 2 Vice yet permit it to rock 'so' thatthe lower end may move outwardly, a cutter on the lower end of thecutter holder, a contractile spring secured to the upper end of eachlcutter holder and also secured in'said body portion tending to withdrawthe cutter holderupward, the upper ends of the cutter holder and theadjacent wall of the body beingbeyeled so that they will cause the lowerend of -the cutter holder to move outward as the cut- 10 ter holder isdrawn upward, substantially as 4set forth.

lj/EDWARD s. HUT'roN.

